Burn-In Environmental Options
Burn-In Process
The burn-in process is performed to screen for and eliminate marginal devices with inherent defects or defects resulting from manufacturing aberrations which cause time and stress dependent failures.
In the absence of burn-in, these defective devices would be expected to result in infant mortality or early lifetime failures under use conditions.
Therefore, this screening process stresses the microcircuits at or above maximum rated operating conditions or applies equivalent screening conditions which will reveal time and stress dependent failure modes with equal or greater sensitivity.
Depending on the customer needs, their devices can be burned in using a voltage bias in High Temperature Operating Life (HTOL) or without a bias in High Temperature Storage Life (HTSL). The difference between the two is described below.
HTOL (High Temperature Operating Life)
This procedure requires devices under test (DUTs) to be subjected to the specification specified burn-in screen test conditions for the required time and temperature of the appropriate device class level. These specifications include: MIL-STD-883 Method 1005.8, JESD22-A108 and EIAJ-ED4701-D323. Also referred to as: BLT (Bias Life Test).
Basic MIL-STD-883 test conditions are as follows:
| Test Condition | Description |
|---|---|
| A | Steady-state, reverse bias |
| B | Steady-state, forward bias |
| C | Steady-state, power and reverse bias |
| D | Parallel excitation |
| E | Ring oscillator |
| F | Temperature-accelerated test |
The ambient burn-in test temperature shall be 125°C minimum for conditions A through E, except for hybrids. At the customer's option, the test temperature for conditions A through E may be increased and the test time reduced accordingly. Below is the applicable MIL-STD-883 Burn-in time-temperature regression table:
| Minimum Temperature TA (°C) |
Minimum Time (hours) | Test Condition | Minimum Reburn-in Time (hours) |
||
|---|---|---|---|---|---|
| Class Level S | Class Level B | Class Level S |
|||
| 100 | 352 | 700 | Hybrids only | 24 | |
| 105 | 300 | 600 | Hybrids only | 24 | |
| 110 | 260 | 520 | Hybrids only | 24 | |
| 115 | 220 | 440 | Hybrids only | 24 | |
| 120 | 190 | 380 | Hybrids only | 24 | |
| 125 | 240 | 160 | 320 | A-E | 24 |
| 130 | 208 | 138 | A-E | 21 | |
| 135 | 180 | 120 | A-E | 18 | |
| 140 | 160 | 105 | A-E | 16 | |
| 145 | 140 | 92 | A-E | 14 | |
| 150 | 120 | 80 | A-E | 12 | |
| 175 | 48 | F | 12 | ||
| 200 | 28 | F | 12 | ||
| 225 | 16 | F | 12 | ||
| 250 | 12 | F | 12 | ||
HTSL (High Temperature Storage Life)
Similar to HTOL above except DUTs are not under a voltage bias while exposed to high temperature. Sometime referred to as “Stabilization Bake.” The procedure can be performed to MIL-STD-883 Method 1008 or JESD22-A103.
Types of Burn-in
There are two ways to burn-in DUTs.
- Static burn-in
- Utilizes only the application of biasing voltage and the necessary temperature to stress the DUTs.
- Dynamic burn-in
- Requires the use of input signals to properly exercise the DUTs in addition to biasing voltage and temperature.
- Requires the use of input signals to properly exercise the DUTs in addition to biasing voltage and temperature.
Equipment Capability
The burn-in chambers used at Golden Altos can meet the following environmental conditions:
- Temperatures to 160°C
- Airflow from 1200 to 1600 CFM
- DC Voltage Range from 1V to 20V ± 10%
- DC Current up to 50 Amps per board
In addition, for static and dynamic burn-in conditions:
- Input Voltage (VIH) Range from 1V to 7V ± 10%
- 96 programmable vector channels
- Pattern depth of 4 Meg
These features ensure the proper stress conditions at any given time. Custom drivers are also available to further boost the available channel capacity of certain burn-in boards.